(Adds details, background)

DUBAI, May 26 (Reuters) - A purported leader of the militant Fatah al-Islam group, which has been battling the Lebanese army in a Palestinian refugee camp, vowed on Saturday to fight "the Americans and the Jews".

Al Jazeera television, which broadcast the videotaped message, identified the man as Shaker al-Abssi and said it was the Palestinian's first public appearance.

"We say to you, the guardians of the American project, the Sunni people will be leaders in fighting the Jews, the Americans and their loyalists," Abssi said, referring to Lebanese leaders.

The channel also aired footage of what it described as training camps for the Islamist group.

Abssi's threat came shortly after the United States delivered ammunition and other equipment to Lebanon to help the army defeat the Islamist group, which is holed up in the Nahr al-Bared refugee camp.

Abssi, bearded and wearing camouflage fatigues, was shown wrapping a black and white chequered scarf around his head. A young militant stood beside him, holding a machine gun.

Fatah al-Islam says it is defending Sunni Muslims and Palestinians in Lebanon. Lebanese Prime Minister Fouad Siniora has described it as a "terrorist organisation that claims to be Islamic and to defend Palestine".

AlertNet news is provided by